1. Technical Field
The present invention relates generally to injecting liquids into gases, and more particularly to spraying liquids into gases at large velocity differences between the gases and sprayed liquids.
2. Description of Related Art
Gas streams from various industrial processes may contain contaminants, such as dissolved species, suspended particulates, and/or other materials (hereinafter: particles). Removal of particles prior to the release of a gas stream to the environment may be required. Some particles may be difficult to remove. Small particles (e.g. below limn, below 100 microns, below 10 microns, below 1 micron, below 1.00 nm, or even below 10 nm) may be especially difficult to remove. In some applications, particles impinging upon or otherwise interacting with a surface may create deposits, which can impede the operation of the apparatus having the particles deposited thereon.
Some processes benefit from controlling a flow rate of a gas stream. Some processes benefit from controlling a pressure associated with a gas stream (e.g., a backpressure). Some gas streams may form deposits on control apparatus, which may impair the ability of the apparatus to control the gas stream.
Some processes create gas streams having suspended particles. Some such processes benefit from precise control of flow rates, pressures, and the like, and may benefit from control of the flow rate and/or pressure drop associated with the particle-laden gas stream. A particle-laden gas stream may be difficult to control, particularly when particles impinge on and/or attach to various mechanisms that control the gas stream. In some cases, a particle-laden gas stream may clog the apparatus that controls flow rate.
Some processes, such as semiconductor processes, may create gas streams that require scrubbing. Scrubbing may include the use of liquids, such as water, which may react with a gas stream. In some cases, reaction with a gas stream creates particles (e.g., SiO2, TiO2, NH4Cl, and the like) which must be removed before being released to the environment. Some reactions create particles, and so subsequent scrubbing applications may benefit from a removal of these particles prior to scrubbing. A wet scrubber may remove some contaminants from a gas stream. For a gas stream containing small particles and a contaminant that reacts with water, scrubbing the gas stream in a wet scrubber may make removal of the particles difficult.